Phototransfer process



PHOTOTRANSFER PROCES S Filed Sept. 24, 1927 MAY CONTAIN SUBSTANCERENDERING CORTING NON-ACTINIC INK IMPENETRHBLE COATING SENSITIZEDEMULSION SH E ET BASE NON-A GTIN I 0 GOAT! N 6 ff dimm flea/woke fikkdaf/gagagvelyer Patented May 30, 1933 UNITED STATES:

PATENT OFFICE 'rnororimivsrnn PROCESS I Application filed September 24,1327. Serial No. 221,853.

This invention relates to aphototransfer process for use in printing orphotography. In the co-pending application of William Heinecke, SerialNo. 189,458, filed May 6, 1927, .there is described a method of makingnegatives, or positives, for printing or photographic purposes,Comprising pulling an inked impression from lithographic stone, copperplate, type, or the like on the sensitive side of a sensitized sheet orphotographic film, plate, or the like, developing the impression,-washing oflf, the ink,.and fixing;

The present invention differs from the former in that the impression ispulled on the non-light sensitive side of a sensitized sheet of paper,film, or the like, and the sheet then exposed with the printed sidetoward the light. After or before being de- 9 veloped the ink impressionis removed and the sheet or film fixed in a suitable 'bath, washed anddried.

The present invention provides a simpler and more economical method inthat a cheaper grade of sensitized material may be used. We havefurtherprovided a specialv protective coating for the material topreventactinic action upon the sensitizing agent so that the process may becarried out 0 in daylight or under artificial light, using ordinary oreven high-speed sensitiveemulsions.

Furthermore, the present invention obvi-' ates the necessity ofreversing the negative when using the negative for printing onsensitized zinc plate for offset'printing. 'Our invention insures closercontact between the negative proper and sensitized side of the zincplate, thereby resulting in a clearer and more sharply defined print.

. to provide a method applicable to offset light in the course ofoperations.

printing, commercial photography and the photographing of finger printsthat will repended claims.

Our invention in its preferred form is illustrated on this accompanyingsheet of drawing.

The sensitized material that is suitable for our process includessensitized paper, film or stripfilm, glass and the like, but we preforto use a paper of fairly cheap stock that 55 is white, or translucent orsemi-translucent, closely formed and hard, of about 0.002 to 0.003 inchin thickness. The sensitive coating is comprised of known emulsions ofsilver halides, ferric compounds, bichromates and other substances, butis preferably an extremely low speed emulsion to enable the operation tobe carried out in daylight or" artificial bright light.

We can, however, use ordinary or high speed emulsionsby employingnon-actinic coatings or desensitizers or both to prevent chemical actionby ordinary exposure to If a fast emulsion, that is, a highly lightsensitive one, is used, the sensitized material isprotected againstlight during operations by a coating of a red-colored solution that willreadily dissolve in the developing solution and on the paper side of thesheet by a coating of yellow colored gelatine solution or other suitablematerial.

Our process has thus obvious advantages over the usual photographicprocesses which require dark rooms, since the printing and It istherefore an object of this invention proof presses, from which theimpressions will be frequently pulled, cannot be installed in dark roomsnor can the usual press rooms be readily converted'into dark 'sensitizerfor use in connection with ordinary or high speed emulsions isphenosafranine.

In order to prevent the ink from penetrating into the paper used forpulling the impressions, we prefer to employ a suitable coating, whichmay be prepared from sodium silicate, lacquer, wax or the like.

There are, however, certain special inks available for our purpose thatdo not require any such coating. By inks, in general, we intend toinclude all inks of a fatty or greasy nature or fats and greases opaquein character that are suitable for our purpose.

The ink, of course, prevents any chemical action on the parts of thesensitized sheet or film covered by the ink, and after the ink has beenremoved by a proper solvent, such as potassium bicarbonate, the freesilver is washed out of said parts to produce a perfect'negative.

Other solvents, such as benzine, ether, spirits of turpentine and thelike may alsobe used, but we prefer potassium bicarbonate because itreadily saponifies the greases or fats of the ink, thereby rendering theoperation clean, while other solvents will soil trays and the hands ofthe operator with ink and will form a film on the fixing bath.

Without limiting our invention to any particular procedure thefollowing. method will serve to illustrate our preferred mode ofoperation.

We start with a sensitized paper such as above described, theunsensitized side of which has been previously coated with a suitablecoating to prevent the ink from penetrating the paper and affecting thelight sens1tive emulsion. Such a coating may be comprised of thefollowing ingredients:

Beesw x 15 grains Rosin 30 grains Gum dammar I 10 grains Benzine 5ounces 7 Spirits of turpentine 5 ounces For the developer, We preferablyuse the following formula:

Ounces Water 32 Sodium sulphite (dry) 5 Hydrochinone 1 Formalin 1 fixingbath,

preferably of the following composition.

- Ounces Water 64 Hypo 16 Stock hardener 8 When the'fixing operation,requiring about one to two minutes, has been completed, the negative isthoroughly washed in several changes of water of medium temperature andis then ready for use.

It will be appreciated that according to our present invention, thenon-sensitive side of the paper having received the inked impression,the negative thus produced will show the type in the same order orarrangement as it occurs on the press. Naturally, if our process is tobe used in offset printing, the regular, or non-readable, arrangement oftype on the press will be employed so that it will not be necessary toreverse the negative in its subsequent application to a sensitized zincplate. This is unimportant feature, as heretofore described, because itresults in clearer and more sharply defined print.

Our process is obviously well adapted not only to offset printing,photo-engraving, and kindred arts, but to commercial photography and tothe recording of finger prints.

We are aware that many changes may be made and numerous details of ourprocess maybe varied through a wide range without departing from theprinciples of this invention, and we therefore do not purpose limitingthe patent granted hereon, otherwise than necessitated by the prior art.

We claim as our invention:

1., As a new article of manufacture, a sensitized sheet having anon-actinic coating on its light sensitive side and a nonactinic and inkimpenetrable coating on its non-sensitized side.

2. As a new article of -manufacture, photo-sensitized sheet materialcomprising a translucent base having a sensitive coating and an outernon-actinic water soluble coating on one side and a non-actinic and inkimpenetrable coating on its reverse side.

3. As a new article of manufacture, a sensitized sheet having anon-actinic coating on its light sensitive side and a yellow, inkimpenetrable coating on its non-sensitized side.

4. As a new article of manufacture, a translucent paper having a lowspeed light sensitive coating on one side and a transparent coatingcomprising Wax, gum dammar, and rosin on the reverse side.

In testimony whereof, We have hereunto subscribed our names at Chicago,Cook County, Illinois.

WILLIAM HEINECKE. FRIEDA HUNSPERGER.

